As sample-surface analysis devices, there exist the following analysis devices: Namely, these devices analyze the sample characteristics by scanning the sample surface with a charged-particle beam probe, and analyzing the amount of emitted signals such as secondary electrons, ions, and electromagnetic waves. This kind of sample-surface analysis devices exhibit an advantage of being capable of easily acquiring information about such factors as the surface's ultra-fine profile and constitution elements. In particular, a scanning electron microscope (: SEM) has come into practical use widely. Here, the scanning electron microscope acquires the surface-profile image by using electrons as the probe, and the secondary electrons as the emitted signal, and by converting the secondary-electron amount into the luminance on the screen. Also, as semiconductor-element inspection devices, inspection devices such as a CD-SEM (: Critical Dimension-SEM) and an inspection SEM have been in wide use in semiconductor fabrication industries. Here, the CD-SEM is a dimension inspection device derived from the scanning electron microscope, and the inspection SEM is a profile inspection device.
A charged-particle beam device, the representative of which is the scanning electron microscope, is a device for irradiating a sample with the beam that is equipped with the electric charge. Accordingly, there exists a possibility that the sample becomes electrified. Consequently, there exists the following possibility: Namely, the electrification, which adhere to the sample, exert an influence on the charged-particle beam, thereby changing the optical condition on the charged-particle beam. The existence of this possibility gives rise to the requirements for accurate detection of the electrification and proper optical-condition adjustment.
In PATENT LITERATURE 1, the explanation has been given concerning the following technique: Namely, large-area electrification, which are accumulated over the entire sample, are measured in such a manner that the measurement on the surface potential using an energy filter is performed at a plurality of measurement points. In PATENT LITERATURE 2 as well, the proposal has been made regarding the following technique: Namely, the electrification amount is determined by the electrification measurement method using the energy filter, or is determined by making the calculation in response to a set magnification.
In PATENT LITERATURE 3, the explanation has been given concerning the following charge-up prevention method for the charged-particle beam device: Namely, in this prevention technique, the voltage to be applied to the sample (i.e., target) is changed. Moreover, a location existing on the insulating-property target and having a linear-line portion is scanned with the electron beam for each of the change. Furthermore, of peaks of a signal obtained by differentiating the secondary-electron signal generated by the scan, the largest peak value is generated at a point-in-time. Then, the applied-voltage value at this point-in-time is applied to the target. In this way, the charge-up of the insulating-property target is eliminated. Also, in PATENT LITERATURE 4 as well, similarly, the explanation has been given regarding the following technique: Namely, a focus shift, which is caused to occur by the electrification accumulated on the sample, is compensated for by analyzing a plurality of scores that are obtained by changing the beam energy.